MAX1964
Tracking/Sequencing Triple/Quintuple Power-Supply Controllers
Lowest Cost, 3- and 5-Output Modem Supplies with Sequencing and Tracking
Top
Overview
Features and Benefits
- 4.5V to 28V Input Voltage Range
- Master DC-DC Step-Down Converter:
- Preset 3.3V or Adjustable (1.236V to 0.75 x VIN) Output Voltage
- Fixed Frequency (200kHz) PWM Controller
- No Current-Sense Resistor
- Adjustable Current Limit
- 95% Efficient
- Soft-Start
- Two (MAX1964)/Four (MAX1965) Analog Gain Blocks:
- Positive Analog Blocks Drive Low-Cost PNP Pass Transistors to Build Positive Linear Regulators
- Negative Analog Block (MAX1965) Drives a Low-Cost NPN Pass Transistor to Build a Negative Linear Regulator
- Power-Good Indicator
- Voltage Sequencing (MAX1964) or Tracking (MAX1965)
Product Details
The MAX1964/MAX1965 power-supply controllers are designed to address cost-sensitive applications demanding voltage sequencing/tracking, such as cable modem consumer premise equipment (CPE), xDSL CPE, and set-top boxes. Operating off a low-cost, unregulated DC supply (such as a wall adapter output), the MAX1964 generates three positive outputs and the MAX1965 generates four positive outputs and one negative output to provide an inexpensive system power supply.
The MAX1964 includes a current-mode synchronous step-down controller and two positive regulator gain blocks. The MAX1965 has one additional positive gain block and one negative regulator gain block. The main synchronous step-down controller generates a high-current output that is preset to 3.3V or adjustable from 1.236V to 0.75 x VIN with an external resistive-divider. The 200kHz operating frequency allows the use of low-cost aluminum-electrolytic capacitors and low-cost power magnetics. Additionally, the MAX1964/MAX1965 step-down controllers sense the voltage across the low-side MOSFET's on-resistance to efficiently provide the current-limit signal, eliminating the need for costly current-sense resistors.
The MAX1964/MAX1965 generate additional supply rails at low cost. The positive regulator gain blocks use an external PNP pass transistor to generate low voltage rails directly from the main step-down converter (such as 2.5V or 1.8V from the main 3.3V output) or higher voltages using coupled windings from the step-down converter (such as 5V, 12V, or 15V). The MAX1965's negative gain block uses an external NPN pass transistor in conjunction with a coupled winding to generate -5V, -12V, or -15V.
All output voltages are externally adjustable, providing maximum flexibility. During startup, the MAX1964 features voltage sequencing and the MAX1965 features voltage tracking. Both controllers provide a power-good output that monitors all of the output voltages.
Applications
- Set-Top Boxes
- Wireless Local Loop (WLL)
- xDSL, Cable, and ISDN Modems
Product Categories
Product Lifecycle
Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Documentation & Resources
Design Resources
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Support & Discussions
Sample & Buy
Ordering FAQs
See our Ordering FAQs for answers to questions about online orders, payment options and more.
Buy Now Pricing
(**) Displayed Buy Now Price and Price Range is based on small quantity orders.
List Pricing
(*)The 1Ku list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.
Lead Times
Please see the latest communication from our CCO regarding lead times.
Sampling
Selecting the Sample button above will redirect to the third-party ADI Sample Site. The part selected will carry over to your cart on this site once logged in. Please create a new account there if you have never used the site before. Contact SampleSupport@analog.com with any questions regarding this Sample Site.